OpenCV获取视频的每一帧并保存为.jpg图片

#include<opencv2/opencv.hpp>#include <iostream>#include <stdio.h>#include<fstream> using namespace std;using namespace cv;//获取视频中的人脸int main(){ //打开视频文件：其实就是建立一个VideoCapture结构  VideoCapture capture("1.mp4"); //检测是否正常打开:成功打开时，isOpened返回ture  if (!capture.isOpened())  cout << "fail toopen!" << endl; //获取整个帧数  long totalFrameNumber = capture.get(CV_CAP_PROP_FRAME_COUNT); cout << "整个视频共" << totalFrameNumber << "帧" << endl; //设置开始帧()  long frameToStart = 1; capture.set(CV_CAP_PROP_POS_FRAMES, frameToStart); cout << "从第" << frameToStart << "帧开始读" << endl; //设置结束帧  int frameToStop = 30; if (frameToStop < frameToStart) {  cout << "结束帧小于开始帧，程序错误，即将退出！" << endl;  return -1; } else {  cout << "结束帧为：第" << frameToStop << "帧" << endl; } //获取帧率  double rate = capture.get(CV_CAP_PROP_FPS); cout << "帧率为:" << rate << endl; //定义一个用来控制读取视频循环结束的变量  bool stop = false; //承载每一帧的图像  Mat frame; //显示每一帧的窗口  namedWindow("Extractedframe"); //两帧间的间隔时间:  //int delay = 1000/rate;  double delay = 1000 / rate; //利用while循环读取帧  //currentFrame是在循环体中控制读取到指定的帧后循环结束的变量  long currentFrame = frameToStart; //滤波器的核  int kernel_size = 3; Mat kernel = Mat::ones(kernel_size, kernel_size, CV_32F) / (float)(kernel_size*kernel_size); while (!stop) {  //读取下一帧   if (!capture.read(frame))  {   cout << "读取视频失败" << endl;   return -1;  }  cout << "正在读取第" << currentFrame << "帧" << endl;  imshow("Extractedframe", frame);  cout << "正在写第" << currentFrame << "帧" << endl;  stringstream str;  str << currentFrame << ".jpg";  cout << str.str() << endl;  imwrite(str.str(), frame);  //waitKey(intdelay=0)当delay≤ 0时会永远等待；当delay>0时会等待delay毫秒   //当时间结束前没有按键按下时，返回值为-1；否则返回按键   //int c = waitKey(delay);  int c = waitKey(1000);  //按下ESC或者到达指定的结束帧后退出读取视频   if ((char)c == 27 || currentFrame > frameToStop)  {   stop = true;  }  //按下按键后会停留在当前帧，等待下一次按键   if (c >= 0)  {   waitKey(0);  }  currentFrame++; } //关闭视频文件  capture.release(); waitKey(0); return 0;}